A caliper brake device for a railway vehicle is installed as a braking device to clamp both sides of a disc that rotates together with the wheel. The caliper brake device (referred to below as a service brake) decelerates and stops the railway vehicle while it is traveling, and also prevents the railway vehicle from moving while stopping (referred to below as a parking brake).
The parking brake device described in Patent Reference 1 actuates a parking brake by using only a spring force of a spring disposed within a brake cylinder which forms the service brake.
However, if a parking brake device is actuated only by the spring force, an axial length of the brake cylinder has to increase because the length of the spring increases. In addition, a mechanism for manually releasing the spring force becomes complicated, because it becomes necessary to use a spring having a large spring force. Moreover, it becomes difficult to install the parking brake device in the existing brake cylinder, because the increased axial length of the brake cylinder also makes the manual release mechanism more complicated, and this also makes the device poorly suited for ordinary use.